① first select the range of areas you want to set.
② find the conditional format and open it.
③ Open the Conditional Formatting dialog box, and then drop the selection formula.
④ input formula:: =sumproduct (($B $: $B $1000= $B 2) * ($C $: $C $1000= $C 2)) >1
⑤ Click Format, choose Font Color.
⑥ Click on the pattern and choose shading.
Click the OK button when the ⑦ setting is complete.
⑧ The final effect looks like this: